A commodity information acquisition and display apparatus constitutes a part of a settlement apparatus to register value information exchanged with a customer as the price of a commodity sold to the customer. As the commodity information acquisition and display apparatus, for example, there is a barcode scanner. The bar code scanner irradiates a laser beam to a barcode symbol attached to each commodity, and captures the laser beam reflected from the barcode symbol.
The barcode symbol is individually read in this way, and the barcode information attached to each commodity is acquired. Each commodity is specified based on the barcode information, and information relating to each commodity, such as price information and name, is displayed on a display.
One of customer's requests to the commodity information acquisition and display apparatus is to confirm consistency between the information displayed on the display and the commodity itself easily and in a short time. As a barcode scanner provided in response to this request, there is known a laser scanner for a barcode reader disclosed in Domestic Re-publication of PCT Application WO91/04550.
This laser scanner is provided on a counter on which a salesclerk performs a check-out operation of a commodity, and is positioned between the salesclerk and a customer who face each other across the counter.
Main parts such as a laser beam scanning optical system including a laser light source, a polygon mirror and the like, and a photoelectric conversion unit are incorporated in the inside of its base. A transparent light guide plate to guide a laser beam to a specified place rises in the vertical direction from substantially the center part of the base.
This transparent light guide plate separates the customer who purchases the commodity and the salesclerk who checks the commodity. A window through which a laser beam freely enters and leaves is provided at the front of the transparent light guide plate on the salesclerk side. A reflective hologram having a special diffraction characteristic is formed at the front (opposite side of the window) of the transparent light guide plate on the customer side. The reflective hologram reflects light of a specific wavelength (for example, green light). On the other hand, light of a wavelength other than the specific wavelength passes through the reflective hologram.
Further, a display whose display screen is directed to the salesclerk side is provided at the end of the base on the customer side. The display screen of the display is also directed to the reflective hologram. The display emits the light of the specific wavelength reflected by the reflective hologram, so that a specified display is performed.
A laser beam generated by the laser light source in the base is incident on the transparent light guide plate, reaches the window while being totally reflected several times in the transparent light guide plate, and outgoes from the window. The laser beam outgoing from the window is reflected by a barcode symbol, again passes through the window, is returned into the transparent light guide plate, and reaches the photoelectric conversion unit in the base. The photoelectric conversion unit performs decoding based on the received light, and outputs barcode information.
In order to cause the laser beam outgoing from the window to be irradiated to the barcode symbol of each commodity, the salesclerk holds each commodity to the window. At this time, an image of each commodity (barcode symbol) held to the window by the salesclerk passes through the window, the transparent light guide plate and the reflective hologram, and is imaged on the retina of the customer. Accordingly, the customer can see the commodity and the barcode symbol held to the window by the salesclerk through the reflective hologram, the transparent light guide plate and the window. At this time, the information image represented by the light of the specific wavelength emitted from the display is reflected and diffracted by the reflective hologram, and enters the eye of the customer. As a result, the customer can overlappingly see a virtual image of price and the like in the vicinity of the commodity (barcode).
However, some customer thinks that when the laser beam irradiated to the commodity (barcode symbol) enters the eye, the health of the eye is damaged. When the laser beam is guided to the window through the transparent light guide plate which the customer directly sees, there is a case where the customer has worry about whether the laser beam is safely guided to the window without being leaked to the outside of the transparent light guide plate at all.
Besides, in the foregoing laser scanner, although the information represented by the display using the light of the specific wavelength is reflected by the special reflective hologram and is visually recognized by the customer, the way of displaying the information as stated above has many problems to be solved.
For example, since the light to represent the information to be seen by the customer does not directly reach the eye of the customer but reaches the eye after being reflected and attenuated by the hologram, the customer sees the information in an unclear state. Especially, since the information seen by the customer is represented by the display using only the light of the specific wavelength reflected by the hologram, it is displayed only with the single color (for example, green), the expressive power is low, and the customer can see only the minimum information such as characters or numerals.
Besides, the display to display the information to the customer is separated from the hologram to approach the customer side, and must be provided between the customer and the hologram. Thus, the customer and the salesclerk are separated, and the communication between both is hampered. Especially, in order to reflect the light representing the information within a suitable angle range, an angle between the hologram and the display is required to be kept at an obtuse angle, not an acute angle, and the distance between the display and the hologram becomes long.
Further, the reflective hologram has a narrow angle range in which light is reflected, and it is difficult to make the range coincident with the view range of every customer, and the information becomes hard to be seen by the customer according to the height of the customer, the standing position or the like.